Definitions

The words and definitions are all here, but I am making the format more readable."(Dan)" preceding the definition means that the word is one I have created and often use in my writings, while all other words are standard to the chess world.

Accidental Error(Dan) - an error made with the best intentions but made due to human calculation error; not a purposeful error

Acquiesce (Dan) - To quickly make a losing move capitulating when there is adequate time on the clock and it was possible that more thought would produce a move that could save the game.

Action Chess A game where each player has 30 minutes to make all his moves.Also known as "Rapid Chess"

Activity(Dan) The positive actions a piece (or pieces) can do in a given positionActual Mobility (Dan)See MobilityAdvance Entries The players who Pre-registered (See "registration") for an event. Usually posted before an event.

Advantage of the two bishops - See "Bishop Pair"

Algebraic NotationA method for writing moves down by using the names of the pieces and the ranks and files. FIDE officially replaced older Descriptive Notation (“P-K4" is now "e4") circa 1970.Amateur In chess, a non-master. At the US Amateur, masters cannot play. At the US Amateur Team tournaments, the team has to average below master rating. Note: in chess, amateurs can win money, sometimes quite a bit at tournaments like the World Open.

AnalysisThe part of the thought process where you generate candidates for both sides (the move tree), e.g. "If I go there, what would he do?"

Annotation To write the story of a game, providing additional text and analysis showing what happened - or could have happened.

Artificially Isolated A pawn that has at least one pawn on a neighboring file, but neighboring pawns are unable to guard or be guarded easily (usually one is stuck on a rank where it cannot support)

Attack 1) When you move a piece to a square where you could capture an opponent’s piece NEXT move. Also, 2) when you have the initiative and can put pressure on specific squares or the opponent's king, e.g. I am attacking the kingside.

Back Rank The rank where a player sets up his major pieces (1st for White; 8th for Black)

Back-Rank Mate A checkmate on the 1st or 8th rank with a Rook or Queen where that piece also covers all the escape squares on that rank. Can also be made on the a or h-files

​Backward Pawn An unguarded pawn which, if you removed all the non-pawns on the board, can move, but eventually pushing it would lose material to opposing pawn captures (even if an adjacent pawn, currently on a lower rank, was able to advance and recapture). A pawn that is fixed (cannot move because another pawn is directly in front, i.e. a "ram") is, by definition not backward. Nor is the rearmost pawn in a pawn chain usually a backward pawn.

Battery Lining up two pieces that move similarly, like a Queen and Rook or Queen and Bishop.

Bishop Pair (The Advantage of...) This is when one player has two Bishops and the other does not. On average, this is worth about half a pawn.

Blitz Fast chess. Many blitz games are 5 minutes per player for the entire game. Chess played at a fast enough time control where good moves are generally less important than the time remaining.

Board Vision (Dan) - The ability to look at a chess board and quickly see what all the pieces are doing (statically). For example, seeing that a bishop on a1 is attacking h8. In Rapid Chess Improvement Michael de la Maza calls this "Chess Vision"

Book Besides the kind with a spine, a “book” move is one that a player has learned to play in a particular position in the opening (from a “book” or other media without the need to “calculate”. All the book moves in a certain opening before a major deviation is a tabiya.

Bookup A chess program that enables one to store moves in a tree from the opening position, train, etc. Now "Chess Openings Wizard"

Blindfold chess A game played where one or both parties are not permitted to look at the board, but must visualize the entire game as they are dictated the opponent's moves.

Blunder A bad move; primarily a move that turns a win into a loss or draw, or a draw into a loss. ANY bad mistake is a blunder - not just a counting mistake, or falling into another tactic.

Botvinnik's Rule A time management principle that states in "normal" openings you want to use roughly 20% of your time for your first 15 moves

Bughouse A variant of chess with two players on each side – a player gets the pieces his partner captures and may place one on an empty square in lieu of a "regular" move.

Bye What you get as a score when you can’t play a round, but still continue to play in the tournament. Byes don’t count for ratings, and can be either 0 points, ½ point, or 1 point (the latter in case you want to play, but are the odd person available). See also "forfeit". Guide to Byes

Calculation The part of analysis involving forced sequences.

Candidate (move) A move under consideration (during the thought process). Some specific types of candidate types: 1) King of the Hill - the best candidate found so far. 2) Initial Candidate (Dan) - any move which does something positive 3) Final Candidate (Dan) - a candidate which is safe (can't easily be defeated by a forcing move)

Candidate Master (CM) - Someone with the International Chess Title for players rated 2200+ FIDE

Capture (or Take) To remove a piece from the board via a legal move - not kill or eat (although other languages use these terms)

Castle Move an unmoved King 2 squares toward an unmoved rook and place the rook on the other side of the king; not a name for a rook.

Check An attack on the King. You do not have to announce “check”.

Checks, Captures, and Threats - (Dan ) The three types of forcing moves. Note that threats to checkmate are more forcing than captures and sometimes even more than checks.

Checkmate An attack on the king where there is no way for your opponent to complete his turn and no longer have the king attacked.

ChessBase An advanced chess database program that enables one to store and search games, etc.

Chess.comThe largest online chess website with almost 6,000,000 members. I had a show "Q&A with Coach Heisman" on Chess.com TV and we have a "Dan Heisman Learning Center" as a group there.

Chess.FMAn online chess radio station open to Internet Chess Club members - Dan had a radio show, "Ask the Renaissance Man", now does Instructional Videos

Chess Maze A type of board vision problem where you move one White piece multiple times in a row to capture the Black king. There are restrictions where it can move, e.g. can't move to squares guarded by Black pieces

Closed Position A position without any open or semi-open files. If some pawns are immobile due to opponent pawns, see "Fixed Pawn Structure"

CM Candidate Master - A FIDE title for those with FIDE ratings 2200-2299 (Dan is a CM).

Complex 1) Complicated (not necessarily chess), also in chess: "Sharp" 2) A set of squares of the same color in one part of the board. e.g. "White has a weak dark square complex on the queenside."

​Consolidation The period after winning material where the side behind in material has the initiative but the side ahead can eventually stabilize and take the initiative with his extra power.

Coordination The ability for various pieces to work together harmoniously to achieve a goal.

Counting (Dan) Seeing if pieces are safe from capturing sequences; the tactic that determines if any forced sequence of captures on any square or squares will gain or lose material.

Critical move A move in a position where the best move(s) are enough better than the second best to make a difference in the expected outcome (win to draw or loss; draw to loss; easy win to difficult win). Critical moves often include complicated decisions, trading pieces, or inflexible plans which cannot be changed. One which should be played carefully and slowly.

Criticality Assessment - The ability to assess how crucial it is to determine the best move(s), i.e., their effect on the possible outcome. (The ability to differentiate the criticality of a move.)

Crosstable A chart showing how each player did in each round.

CTD Club Tournament Director

Dan's Metric (Dan) The move number in a game where you first can state that all your non-pawns (except the King) are developed (active).

Deep Blue The IBM chess playing program, hardware based, which played Garry Kasparov in two world-famous matches in 1996 & 1997, winning in '97.

Descriptive Notation An old chess notation used primarily in English texts including moves such as "P-K4" or "NxB"

Desperado A "hanging" piece that is going to be captured anyway, so it may be able to "sacrifice" itself to get the maximum return.

Discovered Attack An attack by a piece that was opened up via another piece’s move. (also "Discovery")

Discovered Check A discovered attack where the discovered piece also makes a check.

Discovery See Discovered Attack

Domination 1) When a knight or bishop (or any piece) dominates another, by guarding all it's potential moves (see Muller's article) 2) (Dan) when a move, compared to another, has all pros and no cons

Double Attack An attack on two (or more) pieces by a single move

Double check A discovered check where both the discovering and discovered piece both deliver check. In that case, the opposing king must move.

Double Whammy A type of problem where you make two pieces moves in a row for White and leave Black in a legal checkmate. The first move may not be check. See Jeff Coakley's Winning Chess Puzzles for Kids, Vol II

Doubled Pawns Two pawns of the same color on the same file as a result of a capture

Doubled Rooks Two Rooks forming a battery on a rank or file.

Draw NOT “tie” - Any game that ends without either player winning, e.g. stalemate, lack of mating material, 50-move rule, agreed, etc.

En Passant Capturing a pawn that moved 2 spaces with a pawn that could have captured it if it had only moved 1 space, on the next turn only.

En Prise "In take" - able to be captured for free. A piece is en prise if it can be captured but is not guarded. Pronounced "aan-preez"

Endgame The part of the game where the King should come out and fight (with fewer pieces left on the board).

Evaluation Part of the thought process performed at analysis nodes (positions) to determine "Who stands better, how much, and why?"

Exchange (the) Trading a Bishop or Knight for a Rook is winning the Exchange. Losing a Rook for a Bishop or Knight is losing the Exchange. NOT the same as trading pieces.

Expert Someone with a US Chess Federation rating between 2000 and 2199

​Fianchetto To develop a Bishop on a long diagonal (b2 or g2 for White; b7 or g7 for Black).

Forfeit 2 Definitions, depending upon context 1) When you are expected to play in an event, but they don’t show up for their game (which is therefore not rated), or 2) When someone loses on time, a “time forfeit” (which is rated like any other loss)

Fork A double attack, usually by a Knight or Pawn (thus forming a pattern like a “fork” in the road).

Gambit Sacrificing material (usually a pawn) in the opening for a lead in development, open lines, and/or attacking chances

Global Mobility (Dan) See Mobility.

Grandmaster (GM) Someone with the highest International chess title as granted by FIDE

Hand-Waving (Dan) - When you erroneously use general principles to decide upon a move in an analytical position when only careful analysis is required instead.

Helpmate A type of problem where Black moves first and cooperates with White to checkmate Black in a fixed number of moves.

Hole A weak square on the opponent's side of the board.

Hope Chess (Dan) When you make a move without considering whether a possible opponent reply of a check, capture, or threat can be met. My use of Hope Chess was NOT supposed to cover these other "Hope" possibilities: 1) When you make a threat and hope your opponent does not see it, nor 2) When you make a bad move on purpose but hope your opponent makes a worse one 3) You make a unanalyzed move quickly and hope the move/idea/maneuver works anyway

Increment Time (in seconds) added to your clock for each move. For example, in the Team4545 League the time control is 45 45 so you get 45 minutes for the game plus 45 seconds added for each move. As opposed totime-delay

Illegal Move A move that either a) Moves a piece in an illegal manner, or 2) Results in an illegal position, such as leaving the moving player's king in check at the end of the move. An illegal move usually requires pushing the clock; before that it's usually just touch move.

Initiative When your opponent is constantly responding to your forcing moves (checks, captures, and threats). GM Sokolov's interesting, and similar, definition is "When your opponent is more worried about your threats than busy creating his own."

Insufficient Losing Chances - A USCF draw rule where a player with less than two minutes remaining on an analog clock may claim a draw if he thinks he is clearly not losing but is in danger of losing on time. The TD has several options on how to rule, depending on the position. A common ruling is to exchange the analog clock for a time delay clock, but giving the claiming player half of his remaining time.

International Master (IM) - Someone with the "intermediate" International Chess Title

Isolated Pawns Pawns that have no other pawns of the same color on adjacent files.

J'Adoube French. Means "I adjust" - used before touching a poorly placed piece to place it on the center of a square, or to fix a piece accidentally knocked over.

King of the Hill The best candidate move you have found so far. The move which creates the position for which you are trying to find another move which creates a better one.

Knight not Horse – the piece that moves like an “L”

Komodo The chess engine written by Don Dailey and GM Larry Kaufman; when Dailey passed away, Mark Lefler took over as programmer. In 2014- 2016 battling Stockfish for world #1.

Lasker's Rule "If you see a good move, look for a better one" (because you are trying to find the best move you can in a reasonable amount of time).

LPDO Loose Pieces Drop Off (Nunn's Dictum)

LTD Local Tournament Director

Luft German for "air" - a square where the king can escape to prevent back-rank mate, created by moving a pawn.

Master Someone with a US Chess Federation rating between 2200 and 2399 is a national master (NM). There are higher levels of master, both national and international.

Match A series of games with a purpose (as opposed to "game" which is a single contest between two players):1) A set of games between two players, e.g. the "World Championship Match"2) A set of games between two chess teams; e.g. "Our club will play a match against their club"

Mate Short for "Checkmate"

Material Piece value - when you win a pawn, a piece, the Exchange, you are winning "material" On the average a Knight and Bishop are worth 3.5 pawns, a Rook 5.25 pawns, a Queen 10 pawns, and the King has a fighting value of about 4 pawns. Give yourself a bonus of 0.5 pawns if you have the advantage of the Bishop pair. (Value of the pieces courtesy of GM Larry Kaufman)

Mating Material Enough material to checkmate a king by force: queen; rook, 2 bishops, bishop and knight, or pawn (can become queen). Two knights can legally mate but cannot force mate.

Mobility (Dan) The number of moves a piece has. The sub-types:1) Potential mobility - the number of moves a piece has from a given square on an empty board. A queen's potential mobility on e4 is 27. 2) Actual mobility - the number of moves a piece has in a any given position. e.g. In the initial setup, each knight's actual mobility is 2. 3) Global mobility - the number of future squares a piece can land upon in any given position. e.g. A bishop's global mobility is only 32

MCO Modern Chess Openings. A classic opening encyclopedia now in its 15th edition.

Monster (Dan) A piece which is worth considerably more than that piece's normal average value. e.g. "That knight is a monster!"

Open Game A game with multiple open files, especially the d and e-files. Alternately, a game that begins 1.e4 e5.

Outpost A piece guarded in a hole (a weak square on the opponent's side of the board).

Overpreparation (Dan) Taking (wasting) tempos to continue to prepare a move which, if played immediately, would be safe and reasonable anyway.

Patzer; fish A weak chess player

Pawn The weakest and most prevalent chess piece; can promote when reaching the 8th rank to another piece, other than a king.

Pawn Chain A series of pawns on contiguous files, usually where most of the pawns protecting at least one other (see "Pawn island")

Pawn Grabber A player who likes to take pawns even if the resulting gain may be marginal or even negative. If badly negative see "Poisoned Pawn"

Pawn Island A series of pawns on contiguous files; unlike pawn chain, there is no connotation that any pawns need protect each other.

Pawn structure How the pawns for one side are currently placed on the board.

Piece 3 Definitions, depending upon context:1. All the chess men, as in “Get all the pieces out of the bag”2.The non-pawns, as in “You have to develop all your pieces” 3. A Bishop or Knight, as in “I am up (ahead) a piece”

Pin An attack by a Rook, Bishop, or Queen, on a piece that cannot/should not move because a piece behind the attacked piece along the line of attack is worth even more (if the piece behind is a King, this is an “absolute” pin) and the piece is not allowed to move, or it would put the King into check, which is illegal.

Playing Chess Backward (Dan) - Taking too much time on developing moves, and then when the position gets complicated, playing too fast. In other words, playing slowly on non-critical moves and playing quickly on critical moves.

Playing Strength The currently established ability of a player. If a rating were perfect, it would match the playing strength.

Ply A half-move, or the move of one player. When both players move, that is two ply, or one full move.

Poisoned Pawn A pawn that if taken will lead to detrimental play, such as loss of material.

Potential Mobility (Dan) See Mobility

Promote What a pawn does that reaches the other side of the board. The moving player replaces it with a Queen, Rook, Bishop, or Knight on the promoting square. So you can have nine Queens, maximum.

Pseudo-sacrifice A move which gives up material but involves no risk since the player making the move will get back or the material or more (or mate) by force in the next few moves. Many basic combinations start with pseudo-sacrifices, which is why a player cannot reject a candidate move just because it gives up material on the initial sequence. Also known as a sham sacrifice.

Purposeful Error (Dan ) A bad move that violates a principle that was already known by the player. See Accidental Error

PV Principal Variation – the predicted best moves for both sides (usually used in conjunction with computer analysis).

Quick Chess Chess played at a fast time control; for USCF this is usually 5-29 minutes for a game.

Quiescence A position reached in analysis where there are no further forcing moves (checks, captures, or threats) that are likely to change the evaluation of the position. One ideally wants to reach a quiescent position before evaluating

Quiescence Error A common error made by lower rated players where they stop analyzing and evaluate a position when there are still further forcing moves which would likely (or will) change that evaluation

Race chess (Dan) Chess played without an increment or time delay (can deteriorate into a position where whoever moves faster wins)

Ram A pawn of each color fixed against each other on the same file so that neither can move, e.g. White pawn e4, Black pawn e5 (Kmoch: Pawn Power in Chess)

Rank The rows of a chessboard going sideways, numbered 1st-8th starting from White’s side as 1st

Rating A quantitative measure of skill. USCF Ratings are based on a formula originally postulated by Dr. Arpad Elo, and range from roughly 100 for beginners to 3200 for the top computers. Ratings are relative, not absolute, depending upon the population being rated.

Record To write down the moves of a game (verb). The noun is notation. Note that there is no chess verb "notate"

Real Chess (Dan) For every move you consider whether a possible opponent reply of a check, capture, or threat can be met.

Registration The time period before an event where players can sign up and play. To do so before that by phone, mail, etc. is "pre-registration".

Removal of the Guard - A tactical motif where the defender is captured or forced to move so that it is no longer defending. Usually seen in the form of Deflection or Overworked Piece.

Resigns When you purposely turn down your King or say “I resign” – the game is over and you lose. Note that shaking hands does not end a game.

Retained Image The analytical error that occurs deep in a line where a player visualizes a piece as still on a specific square, when in earlier moves of that visualized line it had moved off that square.

Round The game number in a tournament, e.g. I have two wins and one loss and now am going to play round four. A tournament usually has a fixed number of rounds.

Round Robin A system of pairing players where everyone in the same (small) section plays everyone else. Unlike a swiss system, this type of tournament calls for some level of commitment on the part of the players to attempt to complete all their games. The number of rounds in a single round robin is the number of players minus one.

Rut When a player is unable to improve or raise his rating despite consistent effort.

Sandbagger Someone who purposely keeps his rating low in order to qualify for easier sections and a better chance to win money.

Scholar’s Mate To mate on f7 (or, for Black, f2) with a Queen or a Bishop in 4 moves – usually a very bad thing to try. When teaching about this, Dan calls this “Dumb and Dumber”.

Section A part of a chess tournament where the players are paired together. Sections may be divided by rating class, scholastic vs. non-scholastic, rated vs. unrated, Scholastic Level, etc.

Seeds of Tactical Destruction (Dan) Aspects of a position that might allow the opponent to play a tactic, e.g. loose pieces, weak back rank, vulnerable king, pieces along a geometric line, overworked pieces, etc.

Semi-open File A file with only pawns of the opponent. A semi-open game is one where both sides have semi-open (but not open) files.

Semi-stalemate A K&P endgame technique where you "stalemate" an opponent's king (take away all its moves) and force him to make suicidal pawn moves.

Senior Master Someone with a US Chess Federation rating over 2399

Sham sacrifice See pseudo-sacrifice

Simultaneous Exhibition Also called "Simul" - One player plays multiple players at the same time. If the games are not played contiguously but instead a clock is used on each board, that is a "clock-simul"

Skewer/ X-ray Tactical Motif: An inside-out pin. A move that attacks a piece of value, and there is a piece behind it along the line of attack of equal or lesser value that will be attacked anyway if the attacked piece moves.

Skittles Chess for fun or chess without a clock; A skittles room is where you go and play for fun while waiting for your next formal pairing.

Slow chess Chess played at long enough time controls where good moves are generally more important than the time remaining. Usually at least 30 minutes per side.

Slump When a player consistently plays below his normal average playing strength

Sneaky Pin Taking advantage of the squares that a pinned piece is not guarding (Hertan)

Stalemate When the player to move isn’t in check, but none of his pieces can move. This is a type of draw (not all draws are stalemantes!)

STD Senior Tournament Director

Sudden Death A time control period where all the moves have to be played within a certain amount of time (on that player’s clock).

Swindle A successful risk taken when a player is losing and purposely does not play the best move in the hopes that the opponent will make a mistake, and then that happens. A swindle sets a "trap" by making a less-than-optimum move to complicate the position.

Swiss-Sys A software program to pair tournaments and provide tournament information

Swiss System A system of pairing tournaments whereby players are paired against other players who are doing about as well as they are. Wherever possible, players get about an equal number of games with Black and White, and will not play the same opponent twice.

Switcheroo A type of problem where you must switch ANY two pieces on the board and leave Black in a legal checkmate. Switching pawns to the 1st or 8th rank is not allowed. See Jeff Coakley's Winning Chess Puzzles for Kids books

TD Tournament Director (internationally this is an "arbiter")

t/d Time delay - the amount of time a digital clock waits before your official time begins decrementing. Usually this is 5 seconds for over-the-board US Chess Federation play. This differs from an increment, which adds time to your clock.

Tabiya Arabic word originally meaning the opening setup of pieces, but now more commonly used to mean the standard moves of any opening, i.e. the real game starts after the players play the tabiya.

Tablebase A database containing all positions with N or more pieces on the board and the result of that position with perfect play (with either side to move). N is currently 7 but N=6 is widely available.

Tactical Device A tactical idea or set of ideas that can be used in multiple positions. Combining tactical ideas in a similar way in different positions to achieve one or more goals (including the tactical goals of winning material or checkmate).

Tactical Justification Any tactics necessary to show that a move is safe. Usually this means that, at first glance, the move may not look safe, but its safety is ensured by this tactic.

Tactical Vision The ability to spot basic safety issues (motifs like pins, double attacks, removal of the guard, and Counting) when first analyzing a position

Team TournamentA tournament where the players play in rating order, first board against first, second against second, etc. The result is a team win, loss, or draw, depending on whether most of the players win or lose (or half of them do).

Team 4545 An online league which plays on the ICC and provides fun team play at the time control of 45 minutes with a 45 second increment

Tempo The “time” it takes for one of the players to make one move. A “turn”.

The Exchange See "Exchange, the"

Threat A move which can win material, checkmate, or make progress next move if the opponent does not stop it. Attacks on under-defended pieces are a examples of a threat.

Three-Fold Repetition of Position A type of draw where the same position is reached three times with the same player to move. Does not require the same moves and can occur at any point in the game.

Tie When two players have the same score in a tournament or match. Not when a game is drawn.

Tiebreak A method used for differentiating places between two players with the same score. It is usually based on how well the opponents did in an event.

Time Control How much time one has for a game. "G" means all the moves and "SD" is sudden death, meaning that time control requires all the remaining moves must be played in a specified period.

In USCF over-the-board notation use a slash for moves/time: 40/2; SD/1 is 40 moves in 2 hrs followed by all moves in 1 more hr; G/30 all moves in 30 min

Online the two numbers are minutes per game and seconds incremented. So 60 5 is one hour for the game and 5 extra seconds per move.

Time Delay A digital clock is set to NOT run for the first N seconds on each move. Time is not added, as it is with a time increment.

Time Increment See "Increment"

Time Management The skill of taking care of your clock time during a chess game, at two levels: 1) To spend almost all your time for the game ("Macro time management") and 2) Where you spend more time on moves that require it (critical, complicated, etc.) "Micro time management" See The Two Move Triggers

Touch Move The rule that says: 1) If you purposely touch a piece you have to move it, 2) If you let go of a piece you have to leave it there 3) If you purposely displace an opponent’s piece, you have to take it.

Trade To exchange one piece for another of the same or similar value. NOT the same as "the Exchange"

Trap (Opening Trap) A known opening sequence where a player apparently follows good opening principles but the move is not tactically sound. Cambridge Springs trap: 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Bg5 Nbd7 5.cxd5 exd5 6.Nxd5?? Superficially reasonable to grab the pawn when the f-knight is pinned, but... 6...Nxd5! 7.Bxd8 Bb4+ 8.Qd2 Kxd8 and Black will end up ahead a piece. (Compare: Blunder; Swindle)

Trigger One (Dan) Finding a move such that there can't be a better one (thus triggering a player to make that move)

Trigger Two (Dan) A reasonable amount of time to make a move, given the position, the time control, the times on the clock, and possibly the move number.

Two Bishops Short for "The advantage of the two bishops" - See "Bishop Pair"

Two-way bishop (Dan) - a bishop that is strong on both diagonals

Underpromotion When a pawn promotes, but the moving players chooses to get something other than a queen.

Unrated An unrated player who has never played a rated game, or one whose rating has not yet become official. An unrated (or non-rated) game is one that will not be played for a rating.

USATE US Amateur Team East - one of the world's biggest team tournaments, held over President's Day weekend at the Hilton in Parsippany.

Visualization The ability to keep track of where the pieces have moved during lines of analysis

Wallchart A more complete crosstable posted at events showing the player's name, rating, ID, opponents, color each round, and results. Wallcharts show an individual's score cumulatively; crosstables show each game's result

Weak square A square which can no longer be guarded by a pawn.

Wise Adult Syndrome (Dan ) A fast move made with plenty of time on the clock even though the move may be critical and careful analysis was required. Could be due to Hand-waving

Woodpusher A weak chess player

World Champion (WC) - the player who has won the official world championship event (tournament or match). Could be in a particular type, e.g. Junior or Women's World Champion.

Zone of protection (Dan) The area where a (passed) pawn is safe; i.e., "Don't push a passed pawn past its zone of protection.

Zugzwang When one side has to move, but any move is bad. Note: Some contend it is not true zugzwang unless the opponent could not win without this compulsion (in other words, if the player to move could pass but your opponent can still win then, although any move is bad, it is not a true zugzwang).

Zwischenzug An in-between move. For example, after a capture, instead of re-capturing, you give a check first.Sometimes called an "intermezzo".

​960 Chess Also known as Fischer Random chess. A variant where the pieces are placed randomly on the back rank with certain rules such as bishops of opposite colors, king between rooks. There are 960 possible starting configurations.